The effects of two commercially available asphalt modifiers in improving the mechanical properties of asphalt paving mixtures were explored, and the abilities of these modifiers to mitigate pavement distress and improve overall pavement performance were evaluated. Nine binders were formulated with three asphalt grades and two modifiers. The modifiers investigated were carbon black and polymerized asphalt (styrelf). The dense-graded asphalt paving mixture specimens were subjected to dynamic and creep tests at temperatures of 0 deg, 40 deg, 70 deg, 100 deg, and 140 deg f, and the mechanical properties determined were resilient modulus, creep, permanent deformation parameters, and fatigue life. On the basis of these properties, the vesysiiia pavement performance prediction model was used to assess any improvement of the modifier on pavement distress and overall performance. The results indicate that the effect of the modifier on the paving mixture properties is not significant at low temperatures but pronounced at high temperatures. The predicted performance shows that carbon black is the most significant in reducing pavement rutting and polymer is the most significant in reducing fatigue cracking. Bothmodifiers show some degree of improvement in the overall pavement performance. This paper appears in transportation research record no.1317, Asphalt mixtures: design, testing, and evaluation 1991.
Abstract